This invention relates generally to hopper tees used in bulk material handling, and more specifically pertains to a directional hopper tee that blends material dropping vertically therethrough with material entering and passing through horizontally. A unique aspect of this invention is a fluted vertical pipe that begins at the flange. The invention is especially useful for accelerating the unloading of a tank trailer hauling granular bulk material at higher ground clearance.
Hoppers, or tank trailers, regularly transport bulk commodities such as industrial and food products. When the hopper, or tank trailer, reaches its destination, the bulk commodity is unloaded, typically by a power take off driven truck mounted blower or a pneumatic system of a plant or factory. The bulk commodity generally unloads from the hopper and into a pipeline. To complete the unloading, hopper tees are mounted to the discharge outlet of the hoppers, or bins. The hopper tee conventionally has a vertical section of constant dimension and shape and a horizontal section also of constant dimension and shape forming the inverted T shape configuration. To transfer the bulk commodity, the material is moved out of the hopper, or bin, by gravity flow or air pressure vibration into the vertical section of the hopper tee. The clean discharge pipe is connected to the horizontal section of the tee. Pneumatic conveyance of the bulk material through the pipe occurs by establishing a pressure differential in the pipe.
The prior art hopper tees have a complete, one piece assembly that includes a vertical section, connecting to a hopper, and a horizontal section, connecting to a discharge pipe. The prior art hopper tee design fits on the bottom of the bins of pneumatic tank trailers. Typically, the valve of a bin bolts to the flange of the hopper tee. Although prior art hopper tees function well for their intended purposes, some hopper tees lack proper ground clearance for long trailers. Ground clearance has afflicted the tank trailer trucking industry for years. For example, as the hopper tee mounts the tank, ground clearance problems arise when a long trailer, such as a tank trailer, crosses railroad tracks or other uneven surfaces. The longer the trailer, the easier a hopper tee becomes stuck upon a railroad rail, berm, or other short height surface condition. A stuck trailer delays delivery of product to its destination, risks delay penalties to the trucking company, and increases recovery and repair costs of the tank trailers.
The Department of Transportation (DOT) and state highway departments have established heights, widths and lengths the tank trailers must meet. When the hauler transports light density products, such as plastic pellets, the hauler requires a larger cubic foot capacity, or volume, to haul a maximum payload and make hauling such products economically feasible. To increase the cubic foot capacity and remain within DOT height, width and length standards, the prior art and industry have dropped the bottom of the hopper. However, the bottom of the hopper requires angled walls (due to the angle of repose of the bulk material) that funnel down to the hopper tee to allow for emptying of bulk granular material. For most dry bulk products the angle of repose is approximately 45 degrees to the horizontal to obtain the maximum tank volume, in cubic feet, while remaining within the mandated dimensions.